166232421 has 18 divisors (see below), whose sum is σ = 242606598. Its totient is φ = 109682640.

The previous prime is 166232419. The next prime is 166232543. The reversal of 166232421 is 124232661.

166232421 is a `hidden beast` number, since 1 + 6 + 6 + 232 + 421 = 666.

It can be written as a sum of positive squares in only one way, i.e., 85932900 + 80299521 = 9270^2 + 8961^2 .

It is not a de Polignac number, because 166232421 - 2¹ = 166232419 is a prime.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166232021) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 94611 + ... + 96351.

Almost surely, 2^166232421 is an apocalyptic number.

It is an amenable number.

166232421 is a deficient number, since it is larger than the sum of its proper divisors (76374177).

166232421 is a wasteful number, since it uses less digits than its factorization.

166232421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1953 (or 1847 counting only the distinct ones).

The product of its digits is 3456, while the sum is 27.

The square root of 166232421 is about 12893.1152558255. The cubic root of 166232421 is about 549.8428432527.

It can be divided in two parts, 16623 and 2421, that added together give a square (19044 = 138²).

The spelling of 166232421 in words is "one hundred sixty-six million, two hundred thirty-two thousand, four hundred twenty-one".